Door lock



Nov. 27, 1956 Filed July 18, 1955 C. A. ELLIS DOOR LOCK 2 Sheets-Sheet l f 1 it 33 all 32 1311.

INVENTOR AiTORNEYS Nov. 27, 1956 c. A. ELLIS 2,772,108

DOOR LOCK FileciJuly 18, 1955 2 Sheets-Sheei 2 I )9 I 33 5 INVENTOR JM 4- 7 w I FW ATTORNEYS United States Patent DOOR LOCK Charles A. Ellis, Hamden, Conn., assignor to Sargent &

Company, New Haven, Conn., a corporation of Connecticut Application July 18, 1955, Serial No. 522,471

7 Claims. (Cl. 292191) This application relates to a latch bolt for exit door locks or the like, and more particularly to the construction of the bolt head employed in an emergency exit lock mechanism where a tumbling latch bolt is employed.

In many so-called exit locks the bolt head is pivotally attached to the front end of a bolt stem or bolt tail, and the bolt head itself is so supported in the casing that it may swing about its pivot with the stem or tail in either direction. That is to say, in the usual instance the bolt stem is pivoted to the bolt head at substantially the center of the latter while the bolt head at its edges is provided with trunnions or pivot pins supported in cradles in the casing so that the bolt may tumble or swing in either direction about its pivot with the stem depending upon the face of the bolt upon which pressure is applied. That is to say, when the door is closed, pressure would be applied to one face of the bolt by the strike member to cause it to swing or pivot in one direction, while if pressure is applied to the door to move it in an opening direction, pressure would be applied to the other face of the bolt head to cause it to swing or pivot in the other direction.

For this reason the faces of the bolt are so shaped that there is a wedging action between the bolt and the strike or stop member with which the bolt cooperates tending to move the strike member away from the bolt. In some instances where such mechanisms are employed upon double doors, both of which are active, a mullion is employed between the doors upon which the strike member is mounted. This mullion is relatively narrow in order that it occupy as small a space as is possible and hence will flex to some extent when pressure is applied thereto intermediate its upper and lower ends.

Such a deflection will occur when force is applied to the door in an opening direction, for example, by a pull on the outside door trim and, as the bolt face is of curved shape,

the deflection of the mullion causes the force to be applied successively at points further up the latch bolt face or further removed from the pivot of the bolt in the casing. Due to the curved shape of the bolt face this causes the direction of the force to change from that nearly normal to the plane of the door to one nearly parallel to the door or substantially longitudinally of the bolt stem. This often results in an excessive force along the bolt stem which will bend this member or perhaps bulge the latch case itself either at the front or back which will permit retraction of the bolt to a sufiicient extent to allow the door to open.

It is contemplated by the present invention to prevent such an eventuality as that described above. This result is obtained by forming a notch in the face of the bolt head which lies against the strike or stop member when the door is closed, one face of this notch being so directed that the force which will be applied to the door stop by the bolt upon an opening pull upon the door will be normal to the plane of the door and will not effect a wedging action upon the mullion to tend to cause it to flex away from the door.

, 2,772,108 Patented Nov. 27, 1956 The other face of the notch in the latch bolt will be so shaped that upon releasing of an opening force applied to the door, the mullion, if it has been flexed out of position, will return to its original position, camming the bolt into its normal relationship with the strike or stop member.

One object of the present invention is to provide a new and improved form of bolt head for the bolt of an emergency exit latch mechanism. 1

A further object of the invention is the provision of a novel form of bolt head for an emergency exit lock mechanism such that while the bolt will have a generally curved face to permit the usual tumbling movement of the bolt about its pivot, one face of the bolt head will also be pro-. vided with a recess or notch such that the forces applied to the door stop or strike by the bolt upon the application of an excessive pull upon the door will be substantially normal to the plane of the door and will not tend to cause the strike or stop member to move away from the door.

To these and other ends, the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is an elevational view of an emergency exit lock embodying my invention with the cover of the lock casing removed to show the interior mechanism;

Fig. 2 is a sectional view on line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectional view on line 3-3 of Fig. 1, showing the parts of the latch in the position occupied when the door is closed; and

Fig. 4 is a view similar to Fig. 3 showing the parts in position assumed when a force has been exerted upon the door in an opening direction.

To illustrate a preferred embodiment of my invention I have shown a casing 10 adapted to be applied to the inside face of the door 11. This door is adapted to close against a mullion 12, this mullion extending upwardly from the sill to the lintel of the door casing so as to support the movable or swinging edge of the door 11 as well as that of the companion door 13. Upon this mullion is provided a strike or stop member 14 having a portion 15 adapted to be engaged by the head of the latch bolt as will be hereinafter described.

Rockingly mounted in the latch casing is a bolt head 16 of substantially triangular shape, which member is provided with generally curved faces 17 and 18.

Upon its upper and lower sides and at the two corners adjacent its rear face, this bolt head is provided with pins or trunnions 19, these trunnions being mounted in open cradles or sockets 20 provided in the door casing so that when pressure is applied to the face 17 of the bolt head, it will swing about one pair of these trunnions, while when pressure is applied to the face 18 of the bolt head, the latter will swing about the other pair of trunnions. This manner of mounting the bolt head will be understood by those skilled in the art.

Pivoted to the bolt head at 22 substantially intermediate its inner and outer faces is a bolt stem or tail 23, this member being slidably mounted in a bracket 24 and proposition shown, for example, in Figs. 1 and 3.

With this construction it will be noted that the bolt cannot swing about either pair of trunnions unless the stem 23 is permitted to be retracted or moved rear wardly in the case.

The retraction of the stem 23 is normally prevented by the head 29 of a slide 30, this slide being normally held in its operative position shown in Fig. l by a spring 31. The slide 30 may be moved downwardly to its inoperativepo'si ti'on by the door handle 35 (Fig. 3) which is-pivoted by thepin 36 to ea-rs 37 secured to or formed integrally with the casing 10.

This handle is provided with a finger 38 which extends into the 'casingand t-hrough suit-able mechanis-mfactuates the-slide30. This mechanism is 'of the usual 01m old in the art, and hence further description thereoffisnot necessary.

With this construction of the parts it will be seen that when the slide 30 is moved downwardly from the position shown in Fig. 1 against the tension of the spring 31, the stem 23 may be retracted against the force of itsspring 26. Thereupon a force exerted in an opening direction upon the door will cause the curved portion 17 of'th'eface :17 of theboltheadtoengage thep'ortion 15 of the stopor strike 14 and cam the bolt inwardly aboutv the trunnions s'o'as to permit the door to open. Likewisewhen a closing'force i's applied to'the door, the curvedfa'c'e 1'8 of the bolt he'ad will engage the portion 15 of the strike and earn thebol'tinwardly to permit the door =toclose. In each instance when the bolt has cleared the strike member 15, the spring 26- will' force it to its projected position in engagement with the strike.

As shown more especially in Figs. 3 and 4, the face 17 of the boltis provided with a recess; which recess is bounded on one side by the curved face 17*- and upon the other side by a substantially straight or'plane face 17 Thefac'e 17 'is curvedon a suflicient radius as will give a camming action to the bolt as'will be explained later, While the face 17 is cut back slightly with respect to the general plane of the door so that in the position of the parts shown in Fig. 4, as will be explained hereinafter, this face 17 will'engage flatly the adjacent surface of the portion 15 of the strike member.

If; someone attempts to force the door from the outside, for example (it is understood that the handle 35 is on the inside of the door), by a. pull upon the door trim, the generally curved face of the bolt head which is toward the member 15 will effect a camming action on the latter, tending to spring or flex the mullion 12 outwardly away from the door, thus causing the door to openslightly and causing the portion 15 of the strike to ride up the bolt face to some extent to a position nearer the apex 'of'the bolt head.- Thus the application of force to the bolt head would then be in a direction substantially parallel to the face of the door or substantially opposite the pivot 22 and might cause the stem to 'bend or. cause the case to bulge atthe front or back, allowing the bolt head to be retracted to a sufficient extent to permit the door to open.

However, with the provision of the recess in the bolt head bounded by thesurfaces 17 and 17 when the mullion flexes slightly and the door is permitted to open slightly or moved from the closed position shown in Fig. 3 to a position shown in Fig. 4, the .flat' inner surface of the .member. l-engages flatly against the plane face 171 of the recess in the bolt head; When the parts are in this position, a continued opening force applied to the door will not produce a camming action in a direction longitudinally of the stem 23 but will exert a force substantially perpendicular to the plane of the door so that no further wedg'ing of the mullion takes to bend'the stem 23 or bulge the lock case.

Upon removal of a force tending to open the door when the parts are in the position of Fig. 4; the tendency of the mullion to return to its original position will cause the-outer edge of the portion of the strike member to act upon the curved surface 17 and cam the bolt back to the position shown in Fig. 3, thus restoring the parts to their normal relationship and the door to closed position, shown in Fig. 3.

When. the. door is open, the slide is held in its down- Ward inoperative position by the dog-controlling plunger 32, the tail of which acts upon a lever 33 pivoted in the case at 34. The lever 33 has an arm 34 wh-ich engages the slide 30 to move the latter downwardly when the plunger 32 is moved outwardly by its spring 32 in the usual manner.

While I have shown and described a preferred embodiment of my invention, it willbe understood that it is not tobe limited to all of the details. shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims What I claim is:

1. A door lock having a casing and a bolt structure mounted therein to cooperate with a relatively fixed strike member, said structure cornprising a 'bolt head pivoted to the casing to swing about one of its edges when engaged by the strike, said bolt head having a generally curved face engaging the strike when the door is closed whereby the bolthead is cammedinwardly about its pivot when a force is applied'fo the door in an opening direction, and said face of the bolt head having a recess intermediate its ends to receive a portion of the strike when the door is slightly. ajar, and one wall of said recess being adapted to engage flatly against a surface of the strike member. A

2. A door lock having av casing and a bolt structure mounted therein to cooperate with a relatively fixed an opening direction, said face of the bolt head having,

a recess intermediate its ends to receive a portion of the strike when the door is slighty ajar, and one wall of said recess lying in a plane substantially parallel to that of the door to abut fiatly against a surface of the strike- 3. A door lock having a casing and a bolt structure I mounted therein to cooperate with a relatively fixed'stn'k'e member, said structure comprising a bolt head pivoted to the casing to swing about one of its edges when engaged by the strike, said bolt head having a generally curved face engaging the strike when the door 'is closed whereby the bolt head is cammed inwardly about its pivot when a force is applied to the door in an opening direction, said face of the bolt head having a recess intermediate its ends to receive a portion of the strike when the door is slightly ajar, and-one wall of said re cess lying in a plane substantially parallel to-that of the door to abut flatly against a surface of the strike; and

the other wall of the recess being curved whereby pressure of the strike against said curved wall tends to urge the door to closed position.

to the casing to swing about one of its edges-when engaged by the strike, said bolt head having a face gen erally. inclined with respect to the surface ofthe strike whereby the bolt head is cammed inwardly aboutits pivot when a force is applied to t he door' in an opening direction, and said inclined face being provided with a vertical recess intermediateits ends, one wall'of said recess being substantially flat and lying in a plane sub stantially parallel to that of the door, and the inclined face of the bolt head being adapted to engage the strike when the door is in closed position whereby an opening force applied to the door initially tends to cam the bolt head inwardly and exert a force on the strike "tending to force it away from the case, and when 'saidflat pottion of the recess engages the strike, force is applied to the latter in a direction substantially normal tothe plane of the door. 1

5. A door lock having a casing and'a bolt structure mountedtherein to cooperate'with a relatively fixed strike member, said structure comprising'a bolt head pivoted to the casing to swing about one of its edges when engaged by the strike, and a stem pivoted to the bolt head and slidably mounted in the case, said bolt head having a strike-engaging face generally inclined to the longitudinal dimension of the stern whereby the head is cammed inwardly by engagement of said face with the strike, said head having :a vertical recess in said inclined face, and said strike being provided with an angular portion adapted to be received in said recess when the door is slightly ajar, and one wall of said recess abutting flatly against a surface of the strike when the latter is received in the recess.

6. A door lock having a casing and a bolt structure mounted therein to cooperate with a relatively fixed strike member, said structure comprising a bolt head pivoted to the casing to swing about one of its edges when engaged by the strike, and a stem pivoted to the bolt head and slidably mounted in the case, said bolt head having a strike-engaging face generally inclined to the longitudinal dimension of the stem whereby the head is cammed inwardly by engagement of said face with the strike, said head having a vertical recess in said inclined face, and said strike being provided with an angular portion adapted to be received in said recess when the door is slightly aja'r, one wall of said recess abutting flatly against a surface of the strike when the latter is received in the recess, and the other wall of said recess being curved and engaging against the other face of the angular portion of the strike whereby pressure of the strike upon said wall tends to move the door in a closing direction.

7. A door lock having a casing and a bolt structure mounted therein to cooperate with a relatively fixed strike member, said structure comprising a bolt head pivoted to the casing to swing about one of its edges when engaged by the strike, the strike member being mounted upon a yieldable mullion, said bolt head having a camshaped face engaging the strike whereby an opening force applied to the door tends to move said strike and mullion away from the casing, said bolt face having a vertical recess therein, and said strike having an angular portion adapted to be received in said recess when the mullion has been cammed away from the casing and the door is slightly ajar, and one wall of said recess being in a plane parallel to that of the door and engaging flatly against a fiat portion of the strike when the latter is received in said recess.

References Cited in the file of this patent UNITED STATES PATENTS 1,244,443 Hurd Oct. 23, 1917 2,107,299 Kilpatrick Feb. 8, 1938 2,117,715 Godfried May 17, 1938 2,696,398 Teetor Dec. 7, 1954 FOREIGN PATENTS 1,777 Great Britain Feb. 9, 1885 

